Contributing to the debut of various Chinese alternative energy vehicles in the 2008 Beijing Olympics green car fleet, the Volkswagen Group collaborated with Shanghai Auto and scientists at Tongji University to design the Shanghai Volkswagen Passat Lingyu, a zero-emission hydrogen fuel cell vehicle.

This February, 16 of these alternative energy vehicles, equipped with the capacity to travel at speeds of up to 145 km per hour and as far as 235 km on one tank of hydrogen fuel, went on display at California Fuel Cell Partnership in Sacramento.

"The cars run very well," John Tillman, Program Manager for the US Advanced Powertrain Research Program at VW, said.

Currently the partnership is displaying the cars, bringing the total number of exhibited VW fuel cell vehicles to 24, and is taking them on test runs in order to conduct performance evaluations. Ten Chinese technicians will be stationed at the partnership for the next nine months to help maintain them. Together, these vehicles comprise the largest fleet of fuel cell cars from one manufacturer.

Unlike some alternative energy vehicles such as electric cars, these vehicles do not need to be recharged, meaning they can drive for longer distances without stopping.

One of the vehicle's key environmental attractions is that its only by-product emissions are water and oxygen. Its peak energy of 55 kilowatts, obtained by converting hydrogen into water, is fed into a 376-volt lithium-ion battery pack located in the backseat. The fuel cell is charged in part by regenerative braking, a system allowing energy to flow back into the battery when the vehicle has braked.

Still, Tillman cannot predict when the vehicles will be on the market nor how much they will cost - a factor that will fluctuate widely depending on the country in which they are manufactured. The lifespan of the vehicles has also yet to be determined.

Will the Passat Lingyu and other hydrogen vehicles be economically viable in the United States? Tillman feels that the answer is a "chicken-and-egg situation". No one will want to build costly fuel stations until hydrogen fuel is widely commercially available, he said, yet its availability depends on having the infrastructure needed to market and distribute the fuel widely in the first place. There are currently 24 hydrogen fuel stations in California, yet a limited number are open for public use. In addition, only 25 to 30 hydrogen fuel cell cars, all Hondas, have been commercially released worldwide through lease deals.

Tillman predicted that there is a larger market in China than the US for the vehicles, pointing to strong links between government and the private sector - the formula he finds ideal to begin developing the economic conditions for their production.

The Passat Lingyu can also win mass appeal in China, he said, thanks to its sustainability factor.

China has set some of the world's strictest environmental standards in the past few years. In 2003, Beijing set some of the world's strictest energy standards. Additionally, the country as a whole set a goal of reducing its energy consumption by 20 percent between 2005 and 2010, according to the China Sustainable Energy Program, which is headquartered in both San Francisco and Beijing.

The 20 hydrogen fuel cell vehicles used at last year's Olympics, including the 16 Passat Lingyus, were among a total of 500 alternative energy vehicles there. Spectators were also able to travel to events in new biodiesel buses.